214 Dr FoiTy on the Climate of the United States. 



charactei'ised by tlie variations which the temperature of 

 months and seasons experience. But this subject is too ex- 

 tensive for present investigation. It has been already ob- 

 served that the parallels which, in "Western Europe, yield the 

 olive and the orange, are with us productive of ice and snow ; 

 but on the Pacific coast of our territory the requisite tempe- 

 rature is found at Fort Vancouver, which is in the latitude of 

 Montreal. Here vegetation grows luxuriantly in mid-winter. 

 That vegetables common to the warm climates, as the orange, 

 lemon, citron, fig, olive, and pomegranate, can be successfully 

 cultivated here, is no longer a doubtful question ; and the 

 cotton plant also is said to flourish well. The British Fur 

 Company, at Fort Vancouver, besides cultivating all those 

 plants, have likewise a fine grapery, which yields fruit equal 

 to those in France. 



The influence of the unequal distribution of heat upon ve- 

 getable geography is beautifully illustrated in the four systems 

 of climate demonstrated on the same parallels in the Northern 

 Division of the United States ; and if we extend the compa- 

 rison to the Pacific coast, a fifth system may be enumerated 

 on the same latitude. Taking the coast of New England, the 

 region of the great lakes, and the Pacific coast, the diff"erence 

 between the mean temperature of winter and spring varies 

 from 6° 67', to 18° 42' ; while, in the excessive climate of the 

 region west of the lakes, and that intermediate to the lakes 

 and the Atlantic, this difiFerence ranges from 18^ 82' to 30° 83'; 

 and accordingly we find, as already explained, that spring and 

 summer, in the latter, are confounded with each other, and 

 that the sudden excess of heat renders the progress of vege- 

 tation almost perceptible. It is necessary, however, to add, 

 that the low ratio of 6° 67' occurs on the Pacific coast, the 

 lowest average in the Northern Division of the United States 

 being 11° 67'. In the Middle and Southern Divisions, this 

 vernal increase of temperature gradually diminishes, until 

 finally, at Key "We it, it is only 5° 99'. But there is another 

 important feature to be observed. Not only is the vernal in- 

 crease greater in excessive climes ; but as it supervenes upon 

 a lower winter temperature, the efi^ect produced on the de- 

 velopment of vegetation is in an inverse ratio. The vernal 



